[FFmpeg-devel] [PATCH] avformat: add xvag demuxer

Paul B Mahol onemda at gmail.com
Fri Oct 23 14:17:03 CEST 2015


Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavformat/Makefile     |   1 +
 libavformat/allformats.c |   1 +
 libavformat/xvag.c       | 104 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 106 insertions(+)
 create mode 100644 libavformat/xvag.c

diff --git a/libavformat/Makefile b/libavformat/Makefile
index 42b1e19..5ca2843 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -487,6 +487,7 @@ OBJS-$(CONFIG_WV_MUXER)                  += wvenc.o wv.o apetag.o img2.o
 OBJS-$(CONFIG_XA_DEMUXER)                += xa.o
 OBJS-$(CONFIG_XBIN_DEMUXER)              += bintext.o sauce.o
 OBJS-$(CONFIG_XMV_DEMUXER)               += xmv.o
+OBJS-$(CONFIG_XVAG_DEMUXER)              += xvag.o
 OBJS-$(CONFIG_XWMA_DEMUXER)              += xwma.o
 OBJS-$(CONFIG_YOP_DEMUXER)               += yop.o
 OBJS-$(CONFIG_YUV4MPEGPIPE_MUXER)        += yuv4mpegenc.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 5f691ef..69c02b1 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -336,6 +336,7 @@ void av_register_all(void)
     REGISTER_DEMUXER (XA,               xa);
     REGISTER_DEMUXER (XBIN,             xbin);
     REGISTER_DEMUXER (XMV,              xmv);
+    REGISTER_DEMUXER (XVAG,             xvag);
     REGISTER_DEMUXER (XWMA,             xwma);
     REGISTER_DEMUXER (YOP,              yop);
     REGISTER_MUXDEMUX(YUV4MPEGPIPE,     yuv4mpegpipe);
diff --git a/libavformat/xvag.c b/libavformat/xvag.c
new file mode 100644
index 0000000..7ad5ba5
--- /dev/null
+++ b/libavformat/xvag.c
@@ -0,0 +1,104 @@
+/*
+ * XVAG demuxer
+ * Copyright (c) 2015 Paul B Mahol
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/bswap.h"
+#include "avformat.h"
+#include "internal.h"
+
+static int xvag_probe(AVProbeData *p)
+{
+    if (memcmp(p->buf, "XVAG", 4) ||
+        memcmp(p->buf+32, "fmat", 4))
+        return 0;
+
+    return AVPROBE_SCORE_MAX;
+}
+
+static int xvag_read_header(AVFormatContext *s)
+{
+    unsigned offset, big_endian, codec;
+    AVStream *st;
+
+    avio_skip(s->pb, 4);
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
+
+    offset     = avio_rl32(s->pb);
+    big_endian = offset > av_bswap32(offset);
+    if (big_endian) {
+        offset                 = av_bswap32(offset);
+        avio_skip(s->pb, 28);
+        codec                  = avio_rb32(s->pb);
+        st->codec->channels    = avio_rb32(s->pb);
+        avio_skip(s->pb, 4);
+        st->duration           = avio_rb32(s->pb);
+        avio_skip(s->pb, 8);
+        st->codec->sample_rate = avio_rb32(s->pb);
+    } else {
+        avio_skip(s->pb, 28);
+        codec                  = avio_rl32(s->pb);
+        st->codec->channels    = avio_rl32(s->pb);
+        avio_skip(s->pb, 4);
+        st->duration           = avio_rl32(s->pb);
+        avio_skip(s->pb, 8);
+        st->codec->sample_rate = avio_rl32(s->pb);
+    }
+
+    if (st->codec->sample_rate <= 0)
+        return AVERROR_INVALIDDATA;
+    if (st->codec->channels <= 0)
+        return AVERROR_INVALIDDATA;
+
+    switch (codec) {
+    case 0x1c:
+        st->codec->codec_id   = AV_CODEC_ID_ADPCM_PSX;
+        st->codec->block_align = 16 * st->codec->channels;
+        break;
+    default:
+        avpriv_request_sample(s, "codec %X", codec);
+        return AVERROR_PATCHWELCOME;
+    };
+
+    avio_skip(s->pb, offset - avio_tell(s->pb));
+    avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
+
+    return 0;
+}
+
+static int xvag_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    AVCodecContext *codec = s->streams[0]->codec;
+
+    return av_get_packet(s->pb, pkt, codec->block_align);
+}
+
+AVInputFormat ff_xvag_demuxer = {
+    .name           = "xvag",
+    .long_name      = NULL_IF_CONFIG_SMALL("Sony PS3 XVAG"),
+    .read_probe     = xvag_probe,
+    .read_header    = xvag_read_header,
+    .read_packet    = xvag_read_packet,
+    .extensions     = "xvag",
+};
-- 
1.9.1



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